In small-size devices such as a cellular phone, a digital still camera and a digital video camera, printed wiring boards are assembled together to form a desired circuit. As shown in FIG. 7, a connector 30 provided with a socket 31 and a header 32 is used in connecting the printed wiring boards to one another. The socket 31 and the header 32 are mounted to each of the printed wiring boards and are fitted together to electrically connect the printed wiring boards. The connector 30 of this kind is disclosed in Japanese Patent Application Publication No. 2006-210182.
In order to enhance the portability of the devices and to reduce the size thereof, a demand has existed for improvements of the devices. The connector 30 is one of the parts to be improved. It is however difficult to reduce the size of the connector 30, while maintaining the coupling force of the socket 31 and the header 32 and avoiding disconnection or unstable connection between the socket-side electric wiring lines and the header-side electric wiring lines.